Oracle on Monday acknowledged a still-unpatched database vulnerability for which proof-of-concept code was published by a researcher who thought the hole had been plugged.
In its alert, Oracle advised users to apply workaround measures and configuration changes as noted.
The serious vulnerability, which earned a 7.5 CVSS score, is remotely exploitable without the need for authentication by the attacker and affects 10g and 11g (the most current) versions of Oracle Database.
Four years ago, researcher Joxean Koret reported the man-in-the-middle flaw to bug-bounty program iSight Partners, which in turn, shared the details with Oracle per its reward program specifications.
In its quarterly security update two weeks ago, Oracle finally fixed the bug. Or at least that's what Koret thought, considering he was given credit by Oracle in its "Security-In-Depth" program.
Koret said he casually followed up with Oracle to learn which vulnerability he was being credited for -- and then, thinking the coast was clear, published a proof-of-concept for the bug.
But he sent another email to Oracle after being confused by some language in the first exchange. As it turned out, the defect was only repaired in future versions of the database.
He said attackers can exploit the flaw to "sniff any connection" made to the database without the need for credentials, and can also inject malicious commands.
He added that he is not aware of any in-the-wild attacks underway.
In Monday's alert, Oracle said it tries to fix vulnerabilities first in "the main code line" and then "backported" through its quarterly security updates. But sometimes backporting is not possible due to heavy amounts of code required or because doing so will cause serious performance issues for customers.
